Zika virus is a mosquito-transmitted virus that generally causes no symptoms or mild illness, but is associated with microcephaly in infants whose mothers contract it during pregnancy. In January 2016, the US Centers for Disease Control and Prevention (CDC) issued a health advisory, travel alert and MMWR urging women who are pregnant to avoid countries where Zika virus transmission is ongoing. Women trying to become pregnant should consult with their healthcare providers before traveling to these areas and strictly follow steps to avoid mosquito bites during the trip. While cases of Zika have been reported in the United States, as of January 2016 these are limited to patients who recently traveled to countries with Zika transmission. Transmission is not occurring in the US.

Zika virus can be spread from a pregnant woman to her fetus. There have been reports of a serious birth defect of the brain called microcephaly and other poor pregnancy outcomes in babies of mothers who were infected with Zika virus while pregnant. Knowledge of the link between Zika and these outcomes is evolving, but until more is known, CDC recommends special precautions for the following groups:

Women who are pregnant (in any trimester)

Consider postponing travel to any area where Zika virus transmission is ongoing.

If you must travel to one of these areas, talk to your doctor first and strictly follow steps to prevent mosquito bites during your trip.

If you have a male partner who lives in or has traveled to an area where Zika transmission is ongoing, either abstain from sex or use condoms consistently and correctly for the duration of your pregnancy.

Women who are trying to become pregnant:

Before you or your male partner travel, talk to your doctor about your plans to become pregnant and the risk of Zika virus infection.

You and your male partner should strictly follow steps to prevent mosquito bites.

Specific areas where Zika virus transmission is ongoing are often difficult to determine and are likely to change over time.